Methods and vending machines for the dispensing in portions of noncarbonated mixed drinks have been known for a long time. The fruit syrup is usually cooled and is mixed with water, usually tap water, directly during the dispensing operation. In vending machines, it is usually possible to choose between noncarbonated mixed drinks of differing flavors. The choice basically lies between the citrus line (lemon, orange, pineapple) and the line of clear drinks based, for example, on apple syrup or the like. The two lines differ essentially in that the citrus line uses syrups or concentrates which also contain a considerable amount of pulp and lead to cloudy drinks, while the other line uses essentially syrups which lead to clear mixed drinks. Moreover, the citrus syrups are very susceptible to spoilage and must therefore be cooled, for example, to between 4.degree. and 5.degree. C.
Another problem in the production of noncarbonated mixed drinks lies is that the viscosity of the syrups and concentrates varies with temperature. As a change in the syrup temperature within certain limits cannot be prevented with a justifiable outlay for cooling, in spite of the cooling, inaccuracies occur in metering and therefore there are variations in the consistency and quality of the mixed drink. These variations cannot be compensated at the normal injection pressure which is predetermined by the line or top pressure and can be at least 1.5 bar.
An elevation in the injection pressure also fails to solve the problem because a high pressure causes foaming and clouding in the case of mixed drinks using syrups in the clear line, so that apple juice as dispensed can give the impression that it is beer.
For this reason, an injection pressure of approximately 1.5 bar has been maintained in the dispensing of noncarbonated mixed drinks in vending machines and attempts have been made to overcome the other problems by additional cooling and control.